Commit 9085f425 authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: avoid searching twice for previous node when merging free space entries 



At try_merge_free_space(), avoid calling twice rb_prev() to find the
previous node, as that requires looping through the red black tree, so
store the result of the rb_prev() call and then use it.

Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent fbb2e654

fs/btrfs/free-space-cache.c

+6 −3
Original line number Diff line number Diff line
@@ -2449,6 +2449,7 @@ static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl, 
	u64 offset = info->offset;

	u64 bytes = info->bytes;

	const bool is_trimmed = btrfs_free_space_trimmed(info);

	struct rb_node *right_prev = NULL;



	/*

	 * first we want to see if there is free space adjacent to the range we
@@ -2456,9 +2457,11 @@ static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl, 
	 * cover the entire range

	 */

	right_info = tree_search_offset(ctl, offset + bytes, 0, 0);

	if (right_info && rb_prev(&right_info->offset_index))

		left_info = rb_entry(rb_prev(&right_info->offset_index),

				     struct btrfs_free_space, offset_index);

	if (right_info)

		right_prev = rb_prev(&right_info->offset_index);



	if (right_prev)

		left_info = rb_entry(right_prev, struct btrfs_free_space, offset_index);

	else if (!right_info)

		left_info = tree_search_offset(ctl, offset - 1, 0, 0);